OBJECTIVE: To test whether alcohol labels with a cancer warning and national drinking guidelines are an effective tool for supporting more informed and safer alcohol consumption among drinkers. METHODS: Using a quasi-experimental design, pre-post surveys were conducted with 1647 cohort participants systematically selected in liquor stores in two matched sites in Canada in 2017–2018. Enhanced labels designed according to best practices for effective product labels were applied to alcohol containers in the liquor store in the intervention site for one month, and usual practice continued in the comparison site. Generalized estimating equations tested the differences between sites over time in label salience and processing, and self-reported impact of the labels on drinking behaviours. RESULTS: After the intervention, recall of the cancer warning label increased to a greater extent in the intervention versus comparison site (adjusted odds ratio (AOR) = 32.2, 95% CI = 5.4, 191.1), but not the national drinking guideline label (AOR = 2.7, 95% CI = 0.2, 31.8). There were significant label effects in the intervention versus comparison site for reading (AOR = 1.8, 95% CI = 1.3, 2.5), thinking about (AOR = 2.0, 95% CI = 1.4, 2.9), and talking with others about (AOR = 2.1, 95% CI = 1.3, 3.6) the labels, as well as self-reported impact to cut down on drinking (AOR = 2.5, 95% CI = 1.3, 4.7) and to drink less (AOR = 2.4, 95% CI = 1.3, 4.3). CONCLUSIONS: Alcohol labels with a cancer warning and national drinking guidelines do a better job conveying risk information and promoting safer consumption than existing practices. Industry has a legal duty to adequately inform consumers about their products and should be mandated to include key information on alcohol containers. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.17269/s41997-020-00320-7) contains supplementary material, which is available to authorized users.
